Active EMG's have a real "polished" sound to them.
I dont really like them.....but I also don't not like them.
I would defintely not want it as my only pickup option.
My friend was over last weekend and he brought a guitar loaded with EMG 81/85. I have the same guitar loaded with PASSIVE EMG HZ's. (OMG!)
We had a mini ampfest and used the two guitars only.
What I found was the active EMGS were noisier(!) and more prone to feedback. Not much, but it was there. They were tighter sounding, but also a little sterile. Very polished sounding. I would actually like to hear the 85 in the bridge instead.
The passive EMG's weren't as tight sounding, but not to the point of being muddy at all. Still clear and articulate. A bit less output than the 81, but it works to it's advantage IMO.
They were also dead silent, without a instance of hum, hiss or feedback, (unless coaxed)
The passives were also warmer and more natural sounding.
(These EMG passives are about 10 years old, not the crap from the past 4-5 years)
I will like to eventually get some actives, but I won't be replacing the passives when I get them.